Chicago—In a move that apparently reassured investors over his Sears Holdings Corp., Edward Lampert, the company’s chairman and soon-to-be chief executive, revealed Monday that he purchased more than 332,000 additional shares of the retailer.

According to Securities & Exchange Commission filings, Lampert spent more than $13 million of his own money to buy 332,048 shares on Jan. 9 and Jan. 10.

Last week, Lampert announced that he would be assuming the CEO role at the company after Louis D’Ambrosio leaves the job for family health matters in February.